Means for charging circuit breaker contact operating springs



July 27, 1965 w. PATERSON MEANS FOR CHA RGING CIRCUIT BREAKER CONTACT OPERATING SPRINGS 3 Sheets-Sheet 1 Filed Jan. 3, 1963 JMMA 51% 1/9. fn mm July 27, 1965 l. w. PATERSON 3,196,983

MEANS FOR CHARGING CIRCUIT BREAKER CONTACT OPERATING SPRINGS Filed Jan. 3, 1963 3 Sheets-Sheet 2 MEANS FOR CHARGING CIRCUIT BREAKER CONTACT OPERATING SPRINGS Filed Jan. 5, 1963 3 Sheets-Sheet 5 United States Patent 3,196,983 MEANS FUR CHARGING CIRClUlT BREAKER CGNTAQT OPERATLNG SERTNGS Ira W. Paterson, Milton, Mass, assignor to Aliis-ilhaimcrs Manufacturing Company, Milwaukee, Wis. Fiied Jan. 3, 1963, Ser. No. 249,269 6 Claims. (Cl. 185-40) This invention relates generally to electric circuit breaker operating mechanisms employing stored energy operating means such as contact operating springs. More particularly, it relates to means for automatically charging and recharging such contact operating springs.

In some electric circuit breakers, the operating mechanism includes contact operating springs for opening and closing the circuit breaker contacts. Such springs can be charged in advance and then discharged as required to either open or close the circuit breaker contacts rapidly and with great force. In some circuit breakers the contact opening springs are charged upon closure of the contacts. As regards the contact closing springs, means are usually provided so that the springs can be charged manually. However, it is desirable to provide -means for charging the springs automatically so that a human operator need not be present. It is further desirable to do so immediately after the closing springs have been discharged so that they are in readiness to reclose the circuit breaker contacts in the event they trip open.

Accordingly, it is an object of the present invention to provide new and improved means for automatically charging and recharging contact operating springs employed in circuit breaker operating mechanism.

Another object is to provide means of the aforesaid character which comprise an electrical motor operable in response to the condition of the contact operating springs.

Another object is to provide means of the aforesaid character which effect recharging of the contact operating springs immediately after their discharge.

Another object is to provide means of the aforesaid character which employ a minimum number of parts of minimum size and complexity which are relatively easy to fabricate, assemble and maintain. 7

Other objects and advantages of the invention will hereinafter appear.

The present invention is adapted for use with, but not necessarily limited to, a low voltage air circuit breaker of the 600 volt class having supporting means such as a frame which comprises a leg member and a cross member extending laterally therefrom. At least one stationary contact is mounted on the cross member of the frame and a shaft is rotatably mounted on the leg member and extends laterally therefrom. At least one relatively movable contact is connected to the shaft by collapsible offcenter toggle means, a collapsible overcenter toggle means is connected to the offcenter toggle means and to the leg member. When collapsed, the overcenter toggle means opens the movable contact; and when moved overcenter, it closes the movable contact. The overcenter toggle means are moved overcenter by means such as a closing cam which is pivotally mounted on the leg member of the frame. A link is pivotally connected to the closing cam and is movably supported by the leg member. A contact closing spring in the form of a tension spring is connected to the link and to the leg member. The closing cam is movable to a charged position wherein it permits the overcenter toggle means to collapse and wherein it forces the link, and thus the closing spring, to a charged position. Means are provided to latch the link, closing spring and closing cam in the charged position. When unlatched the closing spring discharges and moves the closing cam to a position wherein it moves the overcenter toggle means overcenter and thus effects closing of the movable contact. Means, including manually operable means and electrical drive means, are provided to move the closing cam, link and closing spring to charged position. The manually operable means include a rotatable cam mounted on the leg member and having a manual operating handle. The rotatable cam bears against the closing cam and, when rotated, effects movement of the closing cam to the charged position described above.

In accordance with the present invention, electrical drive means are provided for moving the closing cam, link and closing spring to charged position automatically and independently of the rotatable cam and operating handle.

The electrical drive means comprise an electric motor which is mounted, for example, on the leg member. A pinion gear on the motor shaft drive-s a gear which is rotatably mounted on a movable member or gear frame. The gear frame is movably mounted on the circuit breaker support means as by being pivotally attached at one end to the leg member and is supported at its other end by a spring operated toggle. Though the gear frame and its gear are movable, the gear is adapted so as to always engage the pinion gear. A gear segment is rigidly attached to the closing cam hereinbefore described. The movable gear frame is adapted to assume alternate positions wherein its gear engages or is disengaged from the gear segment. Means are provided to move the gear frame so that its gear moves into engagement with the gear segment when the gear is rotated to a predetermined position. Thus, a leaf spring is attached to the leg member and is positioned so that when the gear is driven by the pinion gear, means such as a projection or pin on the gear engages the leaf spring and causes the gear frame to lift or move to an overcenter position wherein the gear engages the gear segment. The gear frame and its gear are maintained in this position by the spring operated toggle. As the gear rotates, it causes the gear segment to move the closing cam to charged position. Means are provided to move the gear frame so that its gear moves out of engagement with the gear segment when the latter has moved to a position wherein the closing spring is fully charged and latched. Thus, the closing cam or the gear segment is adapted to engage the movable frame and force it out of its overcenter position and into the position wherein its gear is disengaged from the gear segment. Means are provided to control the operation of the motor. It is desired that the motor begin to rotate when the closing spring discharges and that it continue to rotate at least until the closing springs are again fully charged and latched and the projections on the gear are again in position to effect lifting or movement of the gear frame. Accordingly, two motor control switches are provided and connected so that both must be in off position to cause the motor to stop. One switch is responsive to discharge of the closing spring and moves to on when this occurs. This switch may be operated, for example, in response to movement of the link associated with the closing cam. The other switch is responsive to the rotational position of the gear and is maintained on as long as the gear is out of a predetermined position. This other switch may be operated, for example, in response to movement of the pins or projections on the gear as the latter act upon a lever.

The accompanying drawings illustrate a preferred embodirnent of the invention but it is to be understood that the embodiment illustrated is susceptible to modification with respect to details thereof without departing from the scope of the appended claims.

In the drawings:

FIG. 1 is a side elevation View of a circuit breaker q of]? operating mechanism employing stored energy closing means and electric drive means incorporating the present invention and shows the main gear of the drive means disengaged, the closing spring discharged, and the circuit breaker contact closed;

FIG. 2 is a top plan view of the drive means shown in FIG. 3;

FIG. 3 is a view of the drive means shown in BIG. 1 and shows the main gear meshed with the gear segment;

FIG. 4 is a view similar to FIG. 1 but showing the main gear of the drive means disengaged from the gear segment, the closing spring charged, and the contact open;

FIG. 5 is a view taken along line V-V of FIG. 1; and

FIG. 6 is a view taken along line VIVI of FIG. 1.

Referring to FIG. 1, the numeral 10 designates a circuit breaker employing a single center plate mechanism support frame 12. Frame 12 comprises a T-shaped construction employing a single frame leg member 13 which is rigidly attached to a back plate or cross member M which extends laterally from the leg member 13. The leg and cross members 13 and 14, respectively, of the T-shaped frame are mutually braced by side rails, such as the side rail 15 shown, and an apron 17.

Leg member 13 is formed of two flanged pieces 18 and 18' arranged in juxtaposition with their flat surfaces 19, 19 adjacent each other and their flanged reinforcing edges 2d, 20' extending laterally from the flat surfaces outwardly of each other as shown in FIG. 2. At the free end of leg member 13 reinforcement blocks of metal 21 are attached to surfaces 19, 19 and are so formed to provide a cavity 22 extending through the flange surfaces at the free end of the leg member (as shown in FiG. l) for receiving parts of the circuit breaker operating mechanism 28, hereinafter described.

As noted from FIG. 1, cross member 14 is provided with apertures 23, 24 and a flange edge 25 which extends outwardly of the fiat surfaces 26 of cross member 14 toward the leg member 13. A piece of insulating material 27 is mounted on cross member 14 between flange edge 25 with bosses 30 and 31 extending through apertures 23 and 24, respectively, for supporting the current conducting elements on bus bars 32 and 33 of the energizing circuit.

Circuit breaker 1d utilizes a transmission mechanism 35 for actuating a contact controlling mechanism 36. Transmission mechanism 35 comprises manually operable means for charging contact closing springs 5d, hereinafter described, and further comprises electrical drive means for charging the closing springs. The manually operable means of transmission mechanism 35 comprise a pin 37 having rotatably mounted thereon a cam 38. Cam 33 is rotated by a manually rotatable handle 39. Pin 37 extends through cavity 22 of leg member 13 and is rotatably mounted on metal blocks 21. Cam surface 38 is arranged to extend within cavity 22 and upon rotation thereof drives a cam roller 40. Cam roller 4-9 is mounted within cavity 22. on a pin 41.

Pin 41 extends through cavity 22 with the ends thereof loosely mounted in kidney-shaped slots 42, one of which is formed in each of the surfaces of the metal blocks 21. A pair of links 44 (one of which is shown in FIG. 1) are pivotally mounted on pin 41 one at each end of pin 41 between slots 42 and the ends of the pin on each side of leg member 13. The other ends of links 44 are pivotally connected one to each end of a pin 45. Pin 45 is arranged to extend within aligned slots 46 formed in the adjacent surfaces 19, 19 of leg member 13. A pair of resilient rollers 47 are mounted on pin 45 one at each end thereof and come to rest at the bottom of slot 46 against the top of metal blocks 21 mounted on the outside of surfaces 19, 19'. To the ends of pin 45 is fixedly attached a pair of tension springs one arranged on each side of leg member 13. The other ends of springs 50 are fixedly attached to leg member 13 at a pin 51. Thus, upon counterclockwise rotation of handle 39, cam 38 forces roller 4t upwardly along the kidney-shaped slot 42 causing the upward movement of pin 45 and link 44 causing a tensioning or charging of spring 50. A spring biased prop latch 49 bears against roller 40 mounted on pin 41 and holds springs 50 in this charged position.

A motor control switch 48 having a spring biased roller operator 51 is mounted on leg 13 of frame 12 and is adapted to be operated by link 44 as the latter moves upwardly or downwardly. Switch 48 is understood to be part of the electrical drive means hereinafter described and is maintained off or depressed when link 44 is in its uppermost position.

A pair of closing earns 52 having cam surfaces 52 are pivotally mounted between the ends thereof one at each end of a pin 53. Pin 53 is mounted to extend through and be supported by metal bloc {S 21 on surfaces l9, 19' of leg member 13. One end of each of the closing cams 52 is pivotally mounted at different ends of pin 41 outside of the surfaces of block 21. Thus, as pin 41 is pus red upwardly in kidney slots 42, cams 52 are pivoted clockwise about pin 53.

In addition to cam 38 and handle 39 and in accordance with the present invention, electrical drive means are provided to force roller 45) upwardly along slot 52 and cause upward movement of pin 45 and link 44 to cause tensioning or charging of spring 5%. As FIGS.

v 1 through 5 show, the electrical drive means comprise an electric motor 54 which is rigidly mounted on leg member 13 or frame 12. Preferably, to conserve space, motor 54 is mounted on one side of leg 13 and its drive shaft 57 extends through a hole 58 (see FIG. 2) in leg 13 to the other side thereof. Shaft 57 of motor 54 is provided with a rigidly attached pinion gear 59. Shaft 5'7 is understood to rotate in a clockwise direction, as viewed in MG. 1. Pinion gear 59 engages a gear 69 which is rotatable on a pin 73 which is mounted on a movable frame 74. As FIG. .2 shows, frame 74 comprises a pair of spaced apart frame segments 74a and 74b. The innermost segment 74b is provided with a projecting portion on which a roller 79 is mounted. Frame 74 is pivotally attached near one end to leg member 13 by pin 51 and is pivotal thereon. Frame '74 is movably supported at its other end by a spring operated toggle =82. Toggle *82 comprises a link or bar 83 which is pivotally connected at one end to a pin 89 on frame 74 and which is pivotally connected at its other end to a pin 96 on leg member 13 of frame 12. Toggle 82 further comprises a spring 91 which is supported on bar 88 and is compressed between the pins 89 and 99.

Gear 69 is adapted to move into and out of engagement, as will hereinafter appear, with a gear segment 92 which is rigidly attached to one end of the closing earns 52. Gear segment 92 may be attached to closing cam 52 in any suitable manner but it is shown herein as fitting over pin 53 and secured by a nut and bolt assembly 93. The bolt 93a of assembly 93 projects from the side of gear segment 92 and is adapted to engage an auxiliary latching mechanism 94-.

Gear 69 is provided with a pair of projecting members or pins 95 and 96 which extend from one side thereof and are adapted to cooperate with a switch operating lever 97 and a leaf spring 98. Switch operating lever 97 is pivotally mounted on leg 13 of frame 12 at a pivot point 99. In its upper position (see FIGS. 1 and 4) switch operating lever 97 acts upon a spring biased roller operator lliiil of a motor control switch 102 to maintain the latter depressed or off. In its lower position (see FIG. 3) switch operating lever 97 permits switch 162 to bias to on.

Leaf spring 98 is supported on leg 13 of frame 12 on a block N2. When the pins 95 and 96 on gear 69 engage leaf spring 93, frame 74 is biased upwardly and gear 69 meshes with gear segment 92. When frame 74 is biased upwardly, toggle "82 associated therewith moves overcenter, as FIG. 3 shows, and gear 69 and gear segment 92 remains engaged until frame 74 returns to the position shown in FIG. 1 when roller 79 on innermost frame segment 74b is engaged by a cam surface 52a of closing cam 52.

As will be understood, contact mechanism 55 may, for example, include three pairs of cooperating contacts but only one pair is shown 55b and 56b. The relatively stationary contact 56b is mounted on the cross member 14 substantially within the plane of leg member 13. The relatively movable contact 55b is actuated by shaft 72 through toggle 61 to cooperate with stationary contact 55b. In FIG. 1 the contacts are shown in contact closed position before the stored energy springs 51) are charged either by counterclockwise rotation of handle 39 or by operation of the electrical drive means. FIG. 4 shows the contacts in contact open position after the stored energy springs 56 have been charged.

The contact controlling mechanism comprises cooperating overcenter toggle 66 and an offcenter toggle 61. Each toggle arm is understood to comprise a pair of spaced parallelly arranged arm members, however, for purposes of simplification each toggle arm is referred to as a single member. Toggle 66 comprises a pair of toggle arms 62 and 63 interconnected at adjacent ends by a pin passing through a toggle roll 64. Toggle roll 64 is acted upon by closing cam 52. The free end of toggle arm 62 is pivotally mounted on pin 78 passing through kidney-shaped slot 65 in leg member 13. Trip latch 66 is pivotally mounted at 67 on leg member 13 and is biased in a counterclockwise direction by a spring 68. The free end of toggle arm 63 is pivotally connected to the knee of toggle 61. Toggle 61 comprises a pair of toggle arms 78 and 7.1. Toggle arm 76 is fixedly mounted on a shaft 72. Shaft 72 is rotatably attached to the ends of apron 17. Toggle arm 71 is pivotally attached to the movable contact 5512. As shown in FIG. 1 the center movable contact structure 55b of a three phase system is shown wherein the knee of toggle 61 is directly connected to the end of toggle arm 63. As will be understood, the movable contact structures for the other two phases would each employ a toggle 61 which is directly connected through toggle arm 78 to shaft 72 and are actuated thereby. Only the center phase of a three phase system has the knee of its toggle 61 connected to the end of toggle arm 63 of toggle t).

A pair of contact opening tension springs 75 are connected one at each end to flanges 76 fixed to shaft 72. The other end of springs '75 are connected to the circuit breaker frame structure at 77.

With the circuit breaker in open position as shown in FIG. 4, the cooperating toggles 68 and 61 are in their collapsed positions. This collapsed condition is maintainable when the stored energy closing springs 59 are charged since in this condition the closing cam 52 is down and out of the way and cam roller 64 at the knee of toggle 60 can collapse to the left counterclockwise as the breaker contacts open. This function is dependent on releasably restrained connection of toggle arm 62 to trip latch 66 through pin 76.

With the toggles 6t and 61 collapsed as shown in FIG. 4 and springs 59 charged, roller 64 on the knee of toggle 68 moves along the cam surface of closing cam 52.. Spring biased prop latch 49 bears against roller 40 and holds springs 50 in their charged condition. With the release of latch 49 by downward pressure closing cam 52 is rotated counterclockwise driving the roller 64 and the knee of toggle '60 to its overcenter position against a resiliently cushioned stop 88. This motion effects movement of toggle 61 to close the contacts.

Closure of the contacts results in charging of the contact opening springs 75. A component of the opening reaction of springs 75 and contact pressures results in a clockwise rotational bias of trip latch 66. This rotation is controlled by rotary latch 83. Latch 83 comprises a notched pin 84. Clockwise rotation of trip latch 66 causes an edge 85 thereof to be biased against latch 83. A small rotation of latch 83 by the inward movement of release rod 86 releases trip latch 66 and the force of springs 75 and contact pressures revolves trip latch 66 clockwise. The knee of toggle 6d rides vertically downward along the face of the stop 80. Pin 78 at the free end of toggle arm 62 rides downwardly in slot 65 in frame member 13. This downward vertical motion of toggle 60 causes collapse of toggle 61 and opening of the arcing contacts. This action may occur even though closing cam 52 is in the up or spring discharged position shown in FIG. 1.

Rotation of cam 52 away from stop 87 to the charged position of springs 50 as previously described will permit toggle 68 to collapse to the left under the toggle collapsing influence of the toggle breaking spring 81. Thus, the toggle linkage 66 is again in position for a reclosure of the contacts.

A description of the circuit breaker operation is as follows: with the circuit breaker in the open position as shown in FIG. 4 and with the contact open, the double toggles 68 and 61 formed by toggle arms 62, 63 and 70, '71, respectively, are collapsed. This collapsed condition can be maintained only when the stored energy closing springs 56 are charged by counterclockwise rotation of a handle 39 or by operation of the electrical drive means i.e., so that closing cam 52 is in a position where the knee of toggle 66 can collapse to the position shown in FIG. 4. As FIG. 4 shows, link 44 maintains switch 48 closed or off, and since lever 97 maintains switch 102 closed or off, motor 54 will not operate.

To close the contacts of the circuit breaker, toggle must be moved to its overcenter position. This is accomplished by moving downwardly trip latch 49 which releases pin 41 for movement downwardly in slot 42 and under the action of the bias of springs 50 causes closing cam 52 to rotate counterclockwise to move the toggles 68 and 61 thereby closing the contact 55. This position is shown in FIG. 1.

A component of a previous opening reaction provided by accelerating contact opening springs and contact pressures results in a clockwise rotation component of trip latch 66. This rotation is controlled by latch 83.

When springs 56 discharge, link 44 moves to its lower position and switch 48 moves to on thereby causing motor 54 to operate. As will be understood, with the circuit breaker operating mechanism components in the position shown in FIG. 1, motor 54 operates to rotate pinion gear 59 in the clockwise direction and causes gear 69 to rotate in a counterclockwise direction. As gear 69 rotates, the pins and 96 thereon are moved to a pOSition where they bear against resilient leaf spring 98. Leaf spring 98 moves downwardly sufficiently to permit gear 69 to continue to rotate but the force exerted by leaf spring 98 causes gear frame '74 to pivot from the position shown in FIG. 1 to that shown in FIG. 3 which is an overcenter position. As shown in FIG. 3, gear 69 then engages or meshes with gear segment 92 and causes movement of the latter in a clockwise direction. Gear frame 74 is maintained in overcenter position by toggle 82. As gear 69 rotates and the pins 95 and 96 move as above decsribed, they move out of engagement with switch operating lever 97 and the latter moves to the position shown in FIG. 3 wherein it permits switch 102 to turn on.

It is to be noted that in any spur gear train, there is, when operating, an inherent and substantial force component tending to separate the gears and means must be provided to resist this component. In the mechanism disclosed herein, this component is not only resisted but is overcome by a gear relationship which provides a lock-in engaging force which is directly proportional to the load imposed on the gear train; i.e., as the imposed load increases the lock-in force does likewise. The gear arrangement which provides this lock-in feature is described one" as follows. Referring to FIG. 3 it will be seen that the gears are arranged so that the load imposed on gear 69 by the spring force of spring 56 on gear segment @2 acts in one direction (downwardly), and the greater drive force of motor 54 exerted through pinion gear 59 acts in the opposite direction (upwardly). These forces c0- operate with pinion gear 59 and gear segment 92 to p10- vide a force resultant R (which is understood to be greater than separating force resultant R to hold gear 6) in positive engagement against the separating force R as shown in FIG. 3. Thus the necessity for an excessively heavy spring 91 and cooperating supporting means of toggle 82 to hold gear 69 in engagement is avoided.

As gear as continues to move gear segment $2 and closing cam 52 which is attached to the latter, link is again moved to its uppermost position to recharge closing spring 5th and the closing spring becomes latched in charged position. By the time closing spring 5d has been moved to fully charged position, as shown in FIG. 4, the cam surface 52a of closing cam 52 has engaged roller '79 on gear frame segment 74]) and forced gear frame '74 back to its initial position against the restraining action of toggle 82. This effects disengagement of gear from gear segment $2 and movement of the latter is stopped.

Motor 5 continues to operate to rotate gear 69 to the position shown in FIG. 4 even after switch 48 is moved to off by link 44 and thus permits the pins 95 and 96 to assume a predetermined optimum position in readiness for the next recharging cycle. As gear 69 assumes the position shown in PEG. 4, switch operating lever 97 is moved by the pins 95 and W to cause switch 192- to turn oif. 7

Opening of the contacts occurs in the event of even a small rotation of shaft This occurs upon the inward movement of red as shown in PEG. 1. Tie previously referred to force component acting on latch 83 by trip latch 66 revolves trip latch as and causes toggle to ride vertically downward along cam face iii of toggle brealo ing spring 81. This vertical motion of toggle es causes toggle 61 to collapse and the circuit breaker to open even though cam 52 is in the up or spring discharged position shown in FIG. 1.

Rotation of cam 52 to the charged position previously described allows toggle 6-0 to collapse to the left under the influence of toggle breaking spring 81 which bears against the toggle knee. The linkage comprising toggles as and s1 is again in a position for a reclosure operation.

Having now particularly described and ascertained the nature of my said invention and the manner in which it is to be performed, I declare that what i claim is:

]l. In a circuit breaker operating mechanism, in com bination, a contact operating spring, a gear segment linked to said spring and movable to efiect charging of said spring, a rotatable gear for moving said gear segment, said rotatable gear being movable toward and into and away from and out of engagement with said gear seg ment, means cooperating with said gear and responsive to predetermined rotation thereof to effect movement of said gear into engagement with said gear segment, and means cooperating with said gear segment and responsive to predetermined movement thereof to effect movement of said gear out of engagement with said gear segment.

2. In a circuit breaker operating mechanism, in combination, a support, a contact operating spring mounted on said support, a gear segment mounted on said support and movable to effect charging of said spring, a gear frame movably mounted on said support, a rotatable gear mounted on gear frame for moving said gear segment, said gear frame eing movable to move said gear into and out of engagement with said gear segment, and biasing means mounted on said support for engagement with said gear and responsive to rotation of said gear to effect movement of said gear frame and engagement of said gear with said gear segment to effect movement of said gear segment.

3. The combination according to claim 2 wherein predetermined movement of said gear segment effects movement of said gear frame and movement of said gear out of engagement with said gear segment.

4. in a circuit breaker operating mechanism, in combination, a contact operating spring which is chargeable and dischargeable, means including a gear segment linked to said spring and movable to effect charging of said spring, a rotatable gear for moving said gear segment, an electric motor for rotating said gear, a motor control switch responsive to discharge of said spring to effect energization of said motor, means responsive to rotation of said gear for moving said gear toward and into engagement with said gear segment to effect movement of the latter and means responsive to movement of said gear segment for moving said gear away from and out of engagement with said gear segment, and another motor control switch responsive to rotation of said gear after the latter has disengaged the gear segment to effect deenergization of said motor.

5. In a circuit breaker operating mechanism, in combination, a support, a contact operating spring mounted on said support and being chargeable and dischargeable, a gear segment mounted on said support and movable to effect charging of said spring, a gear frame movably mounted on said support, a rotatable gear mounted on said support for moving said gear segment, said gear having a projection thereon, said gear frame being movable to move said gear into and out of engagement with said gear segment, an electric motor for rotating said gear, a motor control switch on said support and responsive to discharge of said contact operating spring to effect energization of said motor, biasing means mounted on said support for cooperation with said projection on said gear when the latter rotates to a predetermined position to move said gear frame so that said gear engages said gear segment, means on said gear segment for cooperation with said gear frame to move said gear out of engagement with said gear segment when the latter has effected charging of said spring, and another motor control switch on said support and responsive to movement of said protection on said gear to another predetermined position after it has been disengaged from said gear segment to effect deenergization of said motor.

6. The combination according to ciaim 5 wherein said motor is rigidly mounted on said support and has a pinion gear which continually engages said rotatable gear as the latter is moved into or out of engagement with said gear segment.

References Cited by the Examiner UNITED STATES PATENTS 1,902,508 3/33 :Learsley 20092 X 2,702,353 2/55 Herson et al. 74397 X 3,019,309 1/62 Goodwin 20050.l5 3,021,400 2/62 Goodwin ZOO-50.15

KULIUS E. WEST, Primary Examiner. 

1. IN A CIRCUIT BREAKER OPERATING MECHANISM, IN COMBINATION, A CONTACT OPERATING SPRING, A GEAR SEGMENT LINKED TO SAID SPRING AND MOVABLE TO EFFECT CHARGING OF SAID SPRING, A ROTATABLE GEAR FOR MOVING SAID GEAR SEGMENT, SAID ROTATABLE GEAR BEING MOVABLE TOWARD AND INTO AND AWAY FROM AND OUT OF ENGAGEMENT WITH SAID GEAR SEGMENT, MEANS COOPERATING WITH SAID GEAR AND RESPONSIVE TO PREDETERMINED ROTATIN THEREOF TO EFFECT MOVEMENT OF SAID GEAR INTO ENGAGEMENT WITH SAID GEAR SEGMENT, AND MEANS COOPERATING WITH SAID GEAR SEGMENT AND RESPONSIVE 